High leakage current in deep sub-micrometer regimes is becoming a significant contributor to power dissipation in Complementary Metal Oxide Semiconductor (CMOS) circuits as threshold voltage (VT), channel length (l) and gate oxide thickness (tox) are reduced. An off current (Ioff) of a transistor includes contributions from at least four types of currents: Gate Leakage current; Junction Leakage current; Source/Drain (S/D) Leakage current; and Band-to-Band Tunneling (SD Edge) current. The leakage currents are generally caused by a voltage difference between two discontinuous media. The detrimental effect of all four types of currents has been enhanced recently as advances are made in the field of shrinking the physical size of CMOS transistors. Minimizing the four types of currents that contribute to the transistor off current has become one of the major issues in all new transistor developments. The transistor off current includes another leakage current, called “sub-threshold leakage current”, which, as the physical size of CMOS transistors shrinks, has been increasing more than the other leakage currents, relatively.